From 7eb038e90ffedc47f75d9dd3e820945a7e8cfcb5 Mon Sep 17 00:00:00 2001
From: AlexKnauth <alexander@knauth.org>
Date: Mon, 16 Oct 2023 17:32:51 -0400
Subject: [PATCH] Support Mac SceneManager

---
 src/game_engine/unity/scene.rs | 56 +++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/src/game_engine/unity/scene.rs b/src/game_engine/unity/scene.rs
index ec99d8d..e98c8eb 100644
--- a/src/game_engine/unity/scene.rs
+++ b/src/game_engine/unity/scene.rs
@@ -11,6 +11,7 @@ use core::{array, iter, mem::MaybeUninit};
 use crate::{
     file_format::pe, future::retry, signature::Signature, string::ArrayCString, Address, Address32,
     Address64, Error, Process,
+    file_format::macho,
 };
 
 const CSTR: usize = 128;
@@ -30,29 +31,50 @@ pub struct SceneManager {
 impl SceneManager {
     /// Attaches to the scene manager in the given process.
     pub fn attach(process: &Process) -> Option<Self> {
-        const SIG_64_BIT: Signature<13> = Signature::new("48 83 EC 20 4C 8B ?5 ???????? 33 F6");
+        const SIG_64_BIT_PE: Signature<13> = Signature::new("48 83 EC 20 4C 8B ?5 ???????? 33 F6");
+        const SIG_64_BIT_MACHO: Signature<13> = Signature::new("41 54 53 50 4C 8B ?5 ???????? 41 83");
         const SIG_32_1: Signature<12> = Signature::new("55 8B EC 51 A1 ???????? 53 33 DB");
         const SIG_32_2: Signature<6> = Signature::new("53 8D 41 ?? 33 DB");
         const SIG_32_3: Signature<14> = Signature::new("55 8B EC 83 EC 18 A1 ???????? 33 C9 53");
 
-        let unity_player = process.get_module_range("UnityPlayer.dll").ok()?;
+        let (unity_player, format) = [("UnityPlayer.dll", BinaryFormat::PE), ("UnityPlayer.dylib", BinaryFormat::MachO)]
+            .into_iter()
+            .find_map(|(name, format)| Some((process.get_module_range(name).ok()?, format)))?;
 
-        let is_64_bit = pe::MachineType::read(process, unity_player.0)? == pe::MachineType::X86_64;
+        let is_64_bit = match format {
+            BinaryFormat::PE => pe::MachineType::read(process, unity_player.0)? == pe::MachineType::X86_64,
+            BinaryFormat::MachO => macho::is_64_bit(process, macho::scan_macho_page(process, unity_player)?)?,
+        };
         let is_il2cpp = process.get_module_address("GameAssembly.dll").is_ok();
 
         // There are multiple signatures that can be used, depending on the version of Unity
         // used in the target game.
-        let base_address: Address = if is_64_bit {
-            let addr = SIG_64_BIT.scan_process_range(process, unity_player)? + 7;
-            addr + 0x4 + process.read::<i32>(addr).ok()?
-        } else if let Some(addr) = SIG_32_1.scan_process_range(process, unity_player) {
-            process.read::<Address32>(addr + 5).ok()?.into()
-        } else if let Some(addr) = SIG_32_2.scan_process_range(process, unity_player) {
-            process.read::<Address32>(addr.add_signed(-4)).ok()?.into()
-        } else if let Some(addr) = SIG_32_3.scan_process_range(process, unity_player) {
-            process.read::<Address32>(addr + 7).ok()?.into()
-        } else {
-            return None;
+        let base_address: Address = match (is_64_bit, format) {
+            (true, BinaryFormat::PE) => {
+                let addr = SIG_64_BIT_PE.scan_process_range(process, unity_player)? + 7;
+                addr + 0x4 + process.read::<i32>(addr).ok()?
+            },
+            (true, BinaryFormat::MachO) => {
+                // RIP-relative addressing
+                // 7 is the offset to the ???????? question marks in the signature
+                let addr = SIG_64_BIT_MACHO.scan_process_range(process, unity_player)? + 7;
+                // 4 is the offset to the next instruction after the question marks
+                addr + 0x4 + process.read::<i32>(addr).ok()?
+            },
+            (false, BinaryFormat::PE) => {
+                if let Some(addr) = SIG_32_1.scan_process_range(process, unity_player) {
+                    process.read::<Address32>(addr + 5).ok()?.into()
+                } else if let Some(addr) = SIG_32_2.scan_process_range(process, unity_player) {
+                    process.read::<Address32>(addr.add_signed(-4)).ok()?.into()
+                } else if let Some(addr) = SIG_32_3.scan_process_range(process, unity_player) {
+                    process.read::<Address32>(addr + 7).ok()?.into()
+                } else {
+                    return None;
+                }
+            },
+            (false, BinaryFormat::MachO) => {
+                return None;
+            },
         };
 
         let offsets = Offsets::new(is_64_bit);
@@ -426,6 +448,12 @@ impl Transform {
     }
 }
 
+#[derive(Copy, Clone, PartialEq, Hash, Debug)]
+enum BinaryFormat {
+    PE,
+    MachO,
+}
+
 struct Offsets {
     scene_count: u8,
     active_scene: u8,